Cut the pepper and sweet potatoes into chunks , the onion into wedges. Leave the skin on the garlic cloves, but crush them with a tenderiser. Cut a long insertion into chillies.
Scatter all vegetables into a large roasting tray. Drizzle with oil, scatter the oregano over them and season with salt and pepper. Combine well then spread everything out in the tray.
Put the tray in a medium hot oven (170-190°C) and roast for approx. 35 minutes until the vegetables are soft and lightly charred.
Serve warm or at room temperature.